Abstract:In this paper, a novel optimization criterion is presented for Adaptive Modulation (AM) Multi-Input and Multi-Output (MIMO) system, which aims at finding out proper modulation and power allocation parameters to reach the required Quality of Services (QoS), while the overall transmission power is minimized. The closed-form solution under perfect Channel State Information (CSI) and the practical algorithm under imperfect CSI are given. The simulation results show that the proposed criterion is very helpful to make cross-layer optimization by taking the QoS requirements into account much easier.